The hybrid electric vehicle (HEV) and the electric vehicle (EV) are currently experiencing a growing demand due to the growing lack of fossil fuels and due to carbon dioxide emissions from exhaust in conventional internal engine vehicles. EVs purely utilize an electric drive motor which is run on electric energy stored in the battery to power the vehicle. HEVs utilize an internal combustion engine and/or electric drive motor to power the vehicle. Hybrid vehicles generally achieve fuel economies which constitute a 25-40% improvement over the conventional internal combustion engine powered vehicles.
Currently the concept of the HEVs/EVs is applied to heavy duty vehicles such as public transport buses. Consider that a public transport bus (electric or hybrid electric bus) with a gross vehicle weight (GVW) of 16 ton typically covers around 200 kilometers in a day's trip in the city. Assuming that the average time the bus spends at a bus stop is around a minute. Also, consider distance between two bus stops that the bus travels in the city route is between 2 km to 5 km. In order to fulfill the above mentioned requirements, the electric or hybrid electric bus, typically, would require a battery to last at least for 200 km for city use. Accordingly, the electric/hybrid bus requires a large battery pack in the range of 200 kwh which may significantly add to the operating cost.
Also, use of a single motor to drive the bus requires a large size motor and heavy weight. Further, a heavy single motor, the higher inertia causes a response lag. Even a single large motor is not able to optimize the battery consumption. Additionally, a multistage gear box needs to be employed to achieve higher speeds.
Therefore, there is a need for a system having one or more motors for converting a vehicle into a hybrid electric vehicle and/or an electric vehicle. The system of the present invention, having multiple motors enables to optimize battery consumption by operating one or more motors according to the torque required to propel the vehicle.